public void Unwrap(int messageLength, byte[] encryptedBuffer,
out byte[] decryptedBuffer)
{
decryptedBuffer = null;
WindowsAPI.SECURITY_HANDLE decryptionContext = _clientContextHandle;
byte[] encryptedMessage = new byte[messageLength];
Array.Copy(encryptedBuffer, 0, encryptedMessage, 0, messageLength);
WindowsAPI.MultipleSecBufferHelper[] secHelper = new WindowsAPI.MultipleSecBufferHelper[2];
secHelper[0] = new WindowsAPI.MultipleSecBufferHelper(encryptedMessage, WindowsAPI.SecBufferType.SECBUFFER_STREAM);
secHelper[1] = new WindowsAPI.MultipleSecBufferHelper(null, WindowsAPI.SecBufferType.SECBUFFER_DATA);
WindowsAPI.SecBufferDesc descBuffer = new WindowsAPI.SecBufferDesc(secHelper);
try
{
uint encryptionQuality = 0;
var ss = WindowsAPI.DecryptMessage(ref decryptionContext, ref descBuffer, 0, out encryptionQuality);
if (ss != WindowsAPI.SEC_E_OK)
{
throw WindowsAPI.CreateException(ss, "DecryptMessage() failed!!!");
}
decryptedBuffer = new byte[messageLength];
Array.Copy(descBuffer.GetSecBufferByteArray(), 0, decryptedBuffer, 0, messageLength);
}
finally
{
descBuffer.Dispose();
}
}
